3.4 Phylogenetic analysis of RV
RV subtypes were identified in 32 RV-positive samples representing
diverse time points by analyzing the VP4/VP2 partial regions, comparing
them with reference strain sequences of RV-A, B, and C found in the
Online 10th Report of the International Committee on Taxonomy of
Viruses. As shown in figure 3, phylogenetic analysis of the VP2-VP4
region disclosed the presence of three RV species among the positive
samples: RV-A, accounting for 46.88% (15 out of 32), RV-B at 6.25% (2
out of 32), and RV-C, also comprising 46.88% (15 out of 32).
Between 2021 and 2023, there were circulation of 23 distinct confirmed
RV subtypes found in this study. RV-A was the most diverse species,
encompassing 11 different types (RV-A7, 20, 29, 30, 49, 55, 58, 60, 66,
78, 80). The most prevalent genotypes identified were RV-A66, RV-A80,
and RV-A20. In the RV-B category, two types were detected: RV-B3 and
RV-B37. As for RV-C, ten different types were noted: RV-C5, C6, C13,
C15, C17, C18, C27, C32, C40, C42, and C88, with RV-C15, RV-C6, and
RV-C13 being the most common (Figure 3). In this investigation, a
notable shift in the dominance between RV-A and RV-C was observed.
During the period from April to June 2022, RV-A exhibited a higher
prevalence, with a ratio of RV-A to RV-C recorded at 4:1. However, in
the latter part of the year, specifically between October and December
2022, the pattern shifted notably, with the prevalence ratio adjusting
to a more balanced 1:1.33. This variation suggests a dynamic pattern in
the circulation and genetic diversity of RV infections among the
pediatric population.